Hewlett received his Bachelor's degree from Stanford University in 1934, a Master of Science degree in electrical engineering from MIT in 1936, and the degree of Electrical Engineer from Stanford in 1939. He joined the Kappa Sigma fraternity during his time at Stanford. In 1999, the William R. Hewlett Teaching Center at Stanford was named in his honor. The building is located in the Science and Engineering Quad, adjacent to the David Packard Electrical Engineering Building.[2]

Hewlett attended undergraduate classes taught by Fred Terman at Stanford and became acquainted with David Packard. Packard and he began discussing forming a company in August 1937, and founded Hewlett-Packard Company as a partnership on January 1, 1939. A flip of a coin decided the ordering of their names.[3] The company incorporated in 1947 and tendered an initial public offering in 1957.[1] Bill Hewlett and Dave Packard were very proud of their company culture which came to be known as the HP Way. The HP Way is a corporate culture that claimed to be not only centered on making money but also respecting and nurturing its employees. Hewlett was president of the Institute of Radio Engineers in 1954.[4] Also in 1939 he married Flora Lamson Hewlett, and the couple eventually had 5 children: Eleanor, Walter, James, William and Mary. There are 12 grandchildren.

He was president of HP from 1964 to 1977, and served as CEO from 1968 to 1978, when he was succeeded by John A. Young. He remained chairman of the executive committee until 1983, and then served as vice chairman of the board until 1987.

A young Steve Jobs, then age 12,[5] called Hewlett (whose number was in the phone book) and requested any available parts for a frequency counter he was building. Hewlett, impressed with Jobs' gumption, offered him a summer job assembling frequency counters. [6] Jobs then considered HP one of the companies that he admired, regarding it among the handful of companies (Disney and Intel were the others) that were built “to last, not just to make money”. [7]